I just bought this Octapad so play with my alternative rock/ electronic band and I am trying to understand its functionality.

I am starting to get used to the features and smoothly setting loops, and did some research about how to further build up my hybrid kit. So I bought roland pd-8 pads and I am thinking about buying the RT triggers for drum and snare, for live settings.

This is where I am confused. Upon attaching the pd-8 to the external trigger inputs..."ride"= ride sound from the pad
"hi hat"= random sounds, high hat bow sounds?
"snare"= switches between "play" and "rec"
"kick"= random kick drums
"hh ctrl"= nothing
footswitch= allows me to use pads to operate the buttons

These triggers are not actually adding more pads on top of the 8 on the octapad? or are they just triggering one of the 8 pads?

Is there a way to specifically control and choose the tones that the external pd-8 will play, or 2 sounds even, since its a dual trigger? (so it plays a tone not already among the 8 on the octapad)

I am trying to figure out how to effectively get the most out of this octapad with my pd-8's! (bought 3 of them used)

And wondering if the RT triggers are something that I should consider buying.

the snare drum input still remainds for switching between PLAY and REC mode.
Is the snare trigger the only one that isnt changeable and assignable?

I don't own a SPD-30, so I'm guessing that maybe the Ext Pad 2 setting in the System Control menu is set to PHRASE-LOOP CTRL, but it should be set to OFF for playing normal Snare sounds - check pages 53&4 in the manual.
If you want to remote control the PHRASE-LOOP CTRL you should try assigning it to a foot switch (in the same menu).